For Nissan 350Z Z33/Infiniti G35 V35 Dual 4.5"Rolled Tip Hi-Power Catback+Header Exhaust System Made of High Quality T-304 Stainless Steel with Computerized Mandrel-Bends for Strength and Durability TIG Welded CNC Machine Flange for Resistance Against Pressure and Corrosion Aggressive Deep and Smooth Tone Sound / Dyno Proven to Instantly Increase 15 - 25 Horsepower or Low End Torque Catback - Dual 4.5" Diameter Muffler Rolled Tip / 2.25" Inlet Header - O2 Sensor Bung Insertion / Metal Gasket Included / 2.25" Inlet / 2.25" Outlet